IMO the factory seat adds negligible structural integrity. In that regard I think removing it is pretty much a non issue. Lots of people cut out the factory seat. I did it to my NDK Poseidon and after all these years ... the darn thing has held it's shape and nothing had been ever been damaged as a result of removing the factory seat. Before you cut it out plan how you want to attach your back band. If you also want to lower your CG by using a foam seat ... be aware that the thinner the foam gets the more fragile your foam seat will be.

Ken Blanton